Continuous connection between the two record classes
Determine whether the Haldane and trivial record classes can be joined continuously, thereby establishing whether a record has phases in the full sense rather than only distinct classes.
References
The transition here is first order because covariance keeps the sectors apart, and whether two classes can be joined continuously would say whether a record has phases in the full sense or only classes.
— Forbidden Subspaces in Quantum State Smoothing
(2609.17307 - Kam et al., 15 Sep 2026) in Conclusion